High pressure tandem turbine

ABSTRACT

The present invention relates to an improved apparatus used for moving gases or air in a single stage for the purposes of either causing a vacuum upstream as in vacuum pumps or high-pressure downstream as in industrial blowers, turbochargers for automotive engines, ducted fan propulsion devices, and compressors for gas turbines. In this improved concept, two matching sets of rotor vanes are paired, rotating in the same direction, without a stator between them, having continuous and progressive pitch angles, the same number of blades, and designed to complement each other. Therefore, the turbo apparatus can yield extreme high-pressure ratios at high flow rates.

CROSS-REFERENCE TO RELATED APPPLICATION

This application claims the benefit of Provisional application Ser. No. 60/590,044, filed Jul. 20, 2004.

FEDERALLY SPONSORED RESEARCH

Not Applicable

SEQUENCE LISTING OR PROGRAM

Not Applicable

BACKGROUND

The present invention relates to an improved apparatus used for moving gases or air for the purposes of either causing a vacuum upstream as in vacuum pumps or high-pressure downstream as in industrial blowers, turbochargers for automotive engines, ducted fan propulsion devices, and compressors for gas turbines.

The practical compression ratio of a typical single stage axial blower is limited approximately to 1.4 to 1.0. To improve this ratio, a typical axial flow gas turbine engine compressor utilizes a series of rotors followed by non-rotating fixed blades, commonly known as stators. Some gas turbines utilize up to 18 sets of rotors and 18 sets of stators to achieve the desired compression ratio. This high number of components makes the overall engine very complex, adding to the number of moving parts and adding the necessity of numerous seals between the stators and the rotors. Each added part adds to the size, weight, complexity, cost and reduced efficiency of the apparatus due to the increased high-speed frictional surface area. Ultimately this results in engines vulnerable to failure.

In radial flow (centrifugal) compressors, the same magnitude of compression may be theoretically achieved by stacking rotors in sequence and with much higher rotational speeds. However, high speeds limit the geometry of the axial compressor design. A high-speed radial flow compressor with anything but a perfectly radial compressor tail fin section will fail due to induced vibrations and centrifugal forces. Stacking in these designs also require cumbersome housing configurations, which add weight and inefficiency.

Although, the following prior art describes improvements related to turbo and gas turbine engines, none of them discloses the specific improvement that the present invention embodies. U.S. Pat. No. 4,512,718 to Stargardter describes a fan rotor assembly for gas turbine engines having decreased susceptibility to vibratory damage. U.S. Pat. No. 5,984,631 to Tolgos presents a tandem turbine-blade cascade for a turbine, turbo-engine or power engine that includes at least two rows of blades disposed substantially directly in line with one another in the rotor or stator. While this art improves over previous designs by reducing the overall number of stages, it is still intended for multiple stages. As a single stage, it could never achieve the high-pressure ratios of the present invention and still maintain sub-sonic blade-tip velocities. Hence, it is a principle object of the present invention to overcome the problems and deficiencies in the art.

It is an object of the present invention to provide an improved apparatus used for moving gases or air in a single stage, for the purposes of either causing vacuum upstream as in vacuum pumps or high-pressure downstream as in industrial blowers, turbochargers for automotive engines, ducted fan propulsion devices, and compressors for gas turbines.

It is another object of the present invention to provide an apparatus that results in an improvement in both efficiency and output over radial flow (centrifugal) compressors.

Still another object of the invention is to provide an apparatus wherein two matching sets of rotor vanes are paired and rotate in the same direction, whereby said apparatus does not comprise of a stator between the two sets of rotors and thereby can yield extremely high-pressure ratios, sufficient even for a jet engine.

A further object of the invention is to provide an apparatus wherein the first and second set of paired rotor blades have continuous and progressive pitch angles, the same number of blades, and are designed to complement each other.

A further object of the invention is to provide a single stage apparatus wherein the first and second set of blades are joined to form a complete single sweep with forward facing trailing ends with or without blunt termination.

These and other objects will become apparent from the following accompanying drawings and description.

SUMMARY

The present invention relates to an improved apparatus used for moving gases or air in a single stage for the purposes of either causing a vacuum upstream as in vacuum pumps or high-pressure downstream as in industrial blowers, turbochargers for automotive engines, ducted fan propulsion devices, and compressors for gas turbines. It has been found that by pairing two matching sets of rotor vanes, rotating in the same direction, without a stator between the two sets of rotors, can yield extreme high-pressure ratios.

In the improved concept, the first and second set of rotor blades are paired, having continuous and progressive pitch angles and the same number of blades designed to complement each other as opposed to each set performing a consecutive or similar operation as in the present state of the art. In certain cases, where extreme high exit velocities are desired without high pressure requirements, as in a leaf blower, ducted-fan propulsion device or a blower used as a cooling device, a single sweep turbo as outlined by FIG. 5 may be used.

BREIF DESCRIPTION OF THE FIGURES

FIG. 1 is an isometric perspective view illustrating the arrangements of two sets of rotor blades on a common hub in accordance with the present invention.

FIG. 2 is a side view showing the end view geometry of the blades attached to a typical common hub.

FIG. 3 illustrates the vector analysis of a tandem turbo of the present invention.

FIG. 4 is a pictorial representation of the airflow pattern departing chaser blades in accordance with the present invention.

FIG. 5 is a side view showing the end view of the single sweep blade attached to a common hub.

FIGURES—REFERENCE NUMBERS

-   10 . . . High Pressure Tandem Turbo -   11 . . . Hub -   12 . . . Chaser Blade -   13 . . . Leading Blade -   14 . . . Accelerated Particles -   100 . . . Apparent Entry Velocity -   101 . . . Intervace Exit/Entry Velocity -   102 . . . Axial Velocity -   103 . . . Chaser Blade Exit Velocity -   104 . . . Apparent Exit Velocity -   105 . . . Radial Velocity at Mean Blade Radius -   106 . . . Degree of Reaction at leading blade -   107 . . . Degree of Reaction at chasing blade

DETAILED DESCRIPTION

The embodiments of the present invention are illustrated as shown in FIGS. 1 through 5. The present invention relates to an improved apparatus 10 used for moving gases or air in a single stage for the purposes of either causing a vacuum upstream as in vacuum pumps or high-pressure downstream as in industrial blowers, turbochargers for automotive engines, ducted fan propulsion devices, and compressors for gas turbines. It has been found that pairing two matching sets of rotor vanes as illustrated by the figures herein, rotating in the same direction, without a stator between the two sets of rotors, can yield extreme high-pressure ratios, sufficient even for jet engines.

In the improved concept, the leading set of rotor blades 13 and chasing set of rotor blades 12 are paired, having continuous and progressive pitch angles, the same number of blades, designed to complement each other as opposed to having each set perform a consecutive or concerted operation as disclosed in the present state of the art. The matching sets of rotor blades are not merely stacked duplicate propeller blades. Rather, they operate at different angles designed to compliment each other. In fact, the chaser blades 12 may not even be functional as fluid moving devices by themselves. They require the leading blades 13 to function in a team effort.

The blades work in pairs much like a tag team; the function of the leading blade 13 is to induce airflow to the chaser blade 12 and to prevent the chaser blade 12 from stalling by controlling the boundary layer. This is achieved by advancing the chaser blade 12 ahead of the leading blade 13 to provide a high-energy stream from the high-pressure side of the leading blade 13 to the low-pressure side of the chaser blade 12. The degree of advance is based on the dynamic boundary layer thickness and the magnitude of work done, i.e., pressure ratios. The leading edge 13 blade in turn benefits from the chaser blade 12 by discharging a portion of the fluid behind the low-pressure side of the chaser blade 12, thereby delaying the choking or cavitation point of the system.

As demonstrated by the figures and illustrations, the leading blade 13 is depicted as having streamlined cross section, tapering off toward its leading and trailing edges. However the trailing blade 12 may have either a streamlined or cleaver like super-cavitating type cross-section depending on the exit velocity of the fluid. While two sets of rotor blades are normally sufficient, a third or even fourth set of matching blades can be configured. In this case, each additional layer would interface with the following layer in the same manner, i.e., a small portion of the high energy fluid stream would be directed at the low pressure side of the following blade to prevent boundary layer separation in the following or the chaser blade 12.

Referring to the drawings, in both FIGS. 1 and 2, the blades are shown as integral part of the entire apparatus 10. This suggests that the blades along with the hub 11 are machined from a common solid bar or made by an investment casting or similar high precision casting or powder metal process. However, the blades can also be individual elements attached and locked to a common hub by means of dovetail or other fastening methods.

The chaser blade's 12 function is clearly visible by lines 101, 103, and 104 as seen in FIG. 3. The marked angle 106 represents the degree of reaction at the leading blade. The marked angle 107 represents the degree of reaction at the chaser blade leading to an angular exit velocity represented by line 104.

The present invention can also be operated with a progressive cavity housing behind the chaser blades, leading to a tangential exit outlet as illustrated by FIG. 4, where greatly accelerated particles 14 exit the chaser blade 12 at high velocity. A side-view of the single sweep bladed turbo is shown in FIG. 5, illustrating how the leading blade, chaser blade, and hub are aligned, and therefore how the blades affect the airflow pattern departing the chaser blades 12.

Although preferred embodiments of the present invention have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.

The present invention relates to an improved apparatus used for moving gases or air for the purposes of either causing a vacuum upstream as in vacuum pumps or high-pressure downstream as in industrial blowers, turbochargers for automotive engines, ducted fan propulsion devices, and compressors for gas turbines.

In the present invention, it has been found that pairing two matching sets of rotor vanes rotating in the same direction, without a stator between the two sets of rotors, in a single stage, can yield extreme high-pressure ratios.

The first and second set of rotor blades that are paired have continuous and progressive pitch angles, the same number of blades, and are designed to complement each other.

The present invention is also an improvement in both efficiency and output over radial flow (centrifugal) compressors.

Although the description above contains much specificity, it should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. 

1. A single stage turbo apparatus comprising: a common hub to support two or more rows of matching sets of rotating rotor blades, with attachment provision to facilitate the connection to a rotating shaft, and two or more rows of matching rotating blades configured in such a manner so that they allow a small portion of the high energy fluid from a leading blade to be directed behind a chaser blade for the purposes of boundary layer control.
 2. The turbo apparatus of claim 1, wherein no stator blades are present between said matching sets of rotor blades.
 3. The turbo apparatus of claim 1, wherein the chaser blades are advanced ahead of the leading set of rotor blades at any angle.
 4. The turbo apparatus of claim 2, wherein the chaser blades are advanced ahead of the leading set of rotor blades at any angle.
 5. The turbo apparatus of claim 1, wherein the fluid flow angle exiting from the leading blade is matched to the entry angle of the chaser blade.
 6. The turbo apparatus of claim 2, wherein the fluid flow angle exiting from the leading blade is matched to the entry angle of the chaser blade.
 7. The turbo apparatus of claim 3, wherein the fluid flow angle exiting from the leading blade is matched to the entry angle of the chaser blade.
 8. The turbo apparatus of claim 4, wherein the fluid flow angle exiting from the leading blade is matched to the entry angle of the chaser blade.
 9. The turbo apparatus of claim 1, wherein the blade pitch at any point for a matched pair of blades is continuous and progressive from the leading blade through the chaser blade, thereby forming a continuous spline contour.
 10. The turbo apparatus of claim 5, wherein the blade pitch at any point for a matched pair of blades is continuous and progressive from the leading blade through the chaser blade, thereby forming a continuous spline contour.
 11. The turbo apparatus of claim 6, wherein the blade pitch at any point for a matched pair of blades is continuous and progressive from the leading blade through the chaser blade, thereby forming a continuous spline contour.
 12. The turbo apparatus of claim 7, wherein the blade pitch at any point for a matched pair of blades is continuous and progressive from the leading blade through the chaser blade, thereby forming a continuous spline contour.
 13. The turbo apparatus of claim 8, wherein the blade pitch at any point for a matched pair of blades is continuous and progressive from the leading blade through the chaser blade, thereby forming a continuous spline contour.
 14. The turbo apparatus of claim 1, wherein a matching pair of leading and chaser blades do not share a common pitch.
 15. The turbo apparatus of claim 1, whereby the trailing edge of the chaser blades are facing forward in the direction of rotation.
 16. The turbo apparatus of claim 1, wherein the angular exit velocity of the fluid is significantly higher than the rotational velocity of the rotor.
 17. A turbo apparatus according to claim 1, where the lead angle between the leading and chaser set of blades is adjustable while in operation, to yield the optimum efficiency possible for a given angular velocity and pressure ratio.
 18. The turbo apparatus of claim 1, wherein the blade pitch at any point for a matched pair of blades is continuous and progressive from the leading blade through the chaser blade, thereby forming a continuous spline contour.
 19. The turbo apparatus of claim 18, wherein the blade pitch at any point for a matched pair of blades is continuous and progressive from the leading blade through the chaser blade, thereby forming a continuous spline contour.
 20. The apparatus of claim 10, wherein the leading and chaser blades are joined to form one single sweep. 